1. Field of the Invention
The present invention relates to image forming apparatuses, image forming systems, and control programs.
2. Description of the Related Art
Conventionally, there are image forming apparatuses, which let the user specify the color of the sheet that is used for printing, and perform the printing while feeding sheets from a sheet feed cassette in which sheets of the color specified by the user have been set (Japanese Patent Laid-Open No. 2002-193465).
In this Japanese Patent Laid-Open No. 2002-193465, the color of the sheets is registered in advance for each cassette tray of the image forming apparatus. After this, if a cassette tray of the image forming apparatus is already set to the color of the sheet specified by the user, then the sheets of this cassette tray are used for printing. If the sheet size or color does not match, then a search is performed on the cassette trays that have not yet been subjected to a search, and if there is no cassette tray corresponding to the specified size and color, then a message is output indicating that there are no sheets. With Japanese Patent Laid-Open No. 2002-193465, the user can print while feeding paper of the desired color to the image forming apparatus, by specifying the sheet colors blue or pink from a driver.
Moreover, conventional image forming apparatuses may include a sheet type database, in which various types of settings for sheets are stored. In this sheet type database, setting parameters that are necessary for printing (such as sheet size or grammage, for example) are collected for each type of sheet. The image forming apparatus can handle any sheet selected by the user from this sheet type database. In this sheet type database, data that corresponds to sheets sold by paper manufacturers is prepared in advance as the various settings that are necessary for printing. The user can print by selecting the suitable data from the paper type database and setting the cassette trays. The setting parameters in the sheet type database include the parameter of sheet color, and by registering the sheets in advance in the sheet type database, the user can confirm the color of the sheets. For example, at the time of printing, the user can specify, with an operating panel, any of the colors (white, blue, cream, bright yellow, grey, green, ivory, orange, pink, red, yellow, transparent, etc.) that have been prepared in advance when registering the sheets.
However, in conventional image forming apparatuses, it may occur that the printing result that is desired by the user is not output when the same color name is registered for sheets of different colors.
For example, user A may register sheets of a dark yellow color in a sheet feed cassette as “yellow” and user B may register sheets of a light yellow color in another sheet feed cassette as “yellow”.
Let us assume that then, user A issues a print instruction specifying “yellow” in order to let the image forming apparatus feed the dark yellow sheets. In this case, the image forming apparatus searches a sheet feed cassette set to “yellow” to feed the sheets therein, but at that time, it is determined that the sheet feed cassette in which user B has set the light yellow sheets matches this condition, and sheets may wind up being fed from that sheet feed cassette. As a result, the light yellow sheets, which were not intended by user A, may be unintentionally used for printing.
Moreover, there are image forming apparatuses that switch the sheet feed cassette to be used, if the number of sheets in the sheet feed cassette is insufficient. Such an image forming apparatus may feed sheets from the sheet feed cassette in which dark yellow sheets are registered as “yellow” and if this sheet feed cassette runs out of sheets, light yellow sheets may be fed from another sheet feed cassette that is also registered as “yellow”. In this case, the color of the print-out will change underway.